docs(blog): restore post 1 forward link to post 2

When post 2 ships, post 1 should point at it. Adds the "Next →" entry
to post 1's series header and restores the closing "the next post is
the demo" line that was stripped when post 1 shipped without its
companions.

Bundling this with post 2 means a single merge does the right thing —
no separate post-publish housekeeping PR.

Author: ojongerius

site/src/content/docs/blog/daemon-process-separation.mdx

@@ -3,7 +3,7 @@ title: "The audit boundary belongs outside the agent"
 description: "The architectural problem with in-process receipt signing, and how daemon process separation restores the audit property."
 ---
 
-_Published 2026-05-17_ · **Series: Auditing AI Agents** · Part 1 of 3
+_Published 2026-05-17_ · **Series: Auditing AI Agents** · Part 1 of 3 · [One Chain, Two Channels, Zero Secrets →](/blog/unified-chain-redaction-demo/)
 
 ---
 
@@ -113,3 +113,5 @@ That signing key — `did:agent-receipts-daemon:local#k1` — lives only in the
 ## What comes next
 
 The daemon is the trust anchor for everything that follows: secret redaction before storage (already shipped), asymmetric payload encryption so only a forensic key holder can read stored inputs, centralised storage for cross-machine audit trails. All of it depends on having one trusted process that owns the keys and the chain.
+
+The next post is the demo — the unified chain and secret redaction working end to end, on real receipts.